Answer:
The focal length of a lens is refers to the distance from the center of the lens to the principal foci.
Infrared radiation<span> lies between the </span>visible<span> and microwave portions of the electromagnetic spectrum. Infrared waves have wavelengths longer </span>than visible<span> and shorter </span>than<span> microwaves, and have </span>frequencies<span> which are lower </span>than visible<span> and </span>higher than<span> microwaves.</span>
Here As we can see the figure that the end of the rope is pulled by some force F
Now as we can see that Piano is connected by a pulley which is passing over the pulley so effectively net force on the piano upwards will be 2F as it is connected by 2 ropes by the pulley
Now for constant velocity of the piano we will say
since velocity is constant so acceleration must be ZERO
so here we have
as we know here that
mg = 1000 N
so we will have
so here force must be 500 N
Answer:
B = 0.546 T, F = 2.59 10⁻¹² N
Explanation:
The magnetic force is
F = q v x B
We can calculate the magnitude of the force and find the direction by the right hand rule
F = q v B sin θ
Let's use Newton's second law
F = m a
Acceleration is centripetal
a = v² / r
We substitute
q v B sin θ = m v² / r
The angle between the field and the radius of the circle is 90º so sin 90 = 1
q B = m v / r
B = m v / q r
Let's calculate ’
B = 1.67 10⁻²⁷ 2.97 10⁷ / (1.60 10⁻¹⁹ 0.568)
B = 0.546 T
The foce is
F = q v B
F = 1.60 10⁻¹⁹ 2.97 10⁷ 0.546
F = 2.59 10⁻¹² N
